Hello,
At my company I have following teams:
- Mobile team
- Backend team
- Frontend team (Admin portal)
- Customer portal team.
Mobile team (4 developers): Currently 90% of the time they are working on app redesign. This should occupy them for ~3 months. This is pure mobile work and does not require backend. 10% of the time they are working on "cross-team" features. Some of this 10% require work from Mobile, Backend, and Frontend teams. Sometimes they just ask Backend team to do a quick fix of something so they can proceed.